Dirty Laundry Meaning

(by metonymy) A clothes hamper or other container in which soiled laundry is placed.

Example:   If you don't tell me why you did it, I'll air all your dirty laundry to your boss.
Laundry that is unclean or soiled
  If you bring your dirty laundry round on Saturday, I'll wash it for you.
  Place your dirty clothes in the dirty laundry.